Can LiDAR penetrate ground?

Can LiDAR Penetrate Ground?

LiDAR, which stands for Light Detection and Ranging, is a remote sensing method that uses light in the form of a pulsed laser to measure variable distances to the Earth. These light pulses—combined with other data recorded by the airborne system—generate precise, three-dimensional information about the shape of the Earth and its surface characteristics.

Ground Penetration Capabilities of LiDAR

LiDAR technology is primarily used for mapping surface features and can be incredibly effective in penetrating vegetation to map the ground beneath forest canopies. However, its ability to penetrate the ground itself, such as soil or sand, is very limited. The primary reason for this limitation is that the laser pulses used in LiDAR are generally absorbed or reflected by the surface of the ground, preventing significant penetration into the soil.

Exceptions and Special Cases

• Topographic LiDAR: This is the most common type of LiDAR used for mapping land surfaces. It emits laser beams towards the ground to measure the distance between the aircraft and the ground. While it can penetrate vegetation to some extent, it cannot penetrate the ground.
• Bathymetric LiDAR: This type of LiDAR is designed to penetrate water and can be used to map the seafloor or riverbeds. It uses green light, which can penetrate water better than the infrared light used in topographic LiDAR. However, its ability to penetrate solid ground is still limited.

Conclusion

In summary, while LiDAR is a powerful tool for mapping and surveying the Earth's surface, its ability to penetrate the ground is minimal. It is effective in penetrating vegetation to reveal the ground surface beneath, but it cannot see through soil or sand to reveal what lies beneath the ground. For subsurface mapping, other methods such as ground-penetrating radar (GPR) are more suitable.